/Engine/Source/Runtime/Engine/Classes/GameFramework/PlayerController.h
Called when the client adds/removes a streamed level. The server will only replicate references to Actors in visible levels so that it's impossible to send references to Actors the client has not initialized.
void ServerUpdateLevelVisibility ( const [FUpdateLevelVisibilityLevelInfo](API\Runtime\Engine\GameFramework\FUpdateLevelVisibilityLevelInfo) & LevelVisibility )